Datasheet and ratings
Identify the proposed model and the electrical ratings that the document must cover.
Request for your projectHEAKOR / Buyer knowledge
Transformer buying,
made clearer.
Practical transformer buying guides for the decisions before a purchase.
Prepare the specification, check document scope and compare proposals on the same basis.
Choose your next task
What are you working on?
01 ↗
Choose a product family
Compare the main transformer arrangements.
02 ↗Prepare your specification
Collect the electrical, site and supply requirements.
03 ↗Send a complete RFQ
Use a practical checklist before requesting prices.
04 ↗Check certificate scope
Match the certificate to the model and rating.
05 ↗Plan a replacement
Record the existing equipment and site constraints.
06 ↗Compare quotations
Check technical scope, documents and commercial terms.
Start here / Procurement essentials
A better enquiry makes a better starting point.
Bring the electrical ratings, site conditions, destination, quantity and required documents together before requesting a quotation.
Open the transformer RFQ checklist- 01Identify the equipment and application
- 02Define electrical and site requirements
- 03List documents and approval needs
- 04Clarify quantity, destination and timing
The guide library
Read. Check. Prepare.
Use these guides to prepare questions for your technical team and supplier. Project documents govern final selection.
22 Oct 2026
Dry-Type Transformer Enclosures: Check IP and Rated Duty Together
Dry-type transformer enclosures need matching IP evidence and a thermal-duty review. Confirm that the proposed drawings, cooling arrangement and rated duty d...
Read the guide
21 Oct 2026
Transformer Spare Parts List: Commissioning & Operating Spares
A transformer spare parts list separates installation items, commissioning provisions and operating spares. Check part references, quantities, approvals, pac...
Read the guide
21 Oct 2026
Transformer Auxiliary Power: Liquid-Filled Supply Scope
Transformer auxiliary power needs a clear load list and supply boundary. Confirm fitted accessories, available AC/DC sources, incoming terminals, cable scope...
Read the guide
21 Oct 2026
Transformer Oil Level Indicator: Conservator & Gauge Match
A transformer oil level indicator must match its oil compartment and conservator arrangement. Review the selected model, mounting, float geometry, dial basis...
Read the guide
20 Oct 2026
Split-Shipped Substation Transformers: Agree Site Reassembly Scope
Split-shipped substation transformer procurement requires clear site responsibilities. Use a stage-by-stage matrix to agree preparation, reassembly, supervis...
Read the guide
20 Oct 2026
Transformer FAT Witness and Hold Points: Agree the Release Process
Transformer FAT witness and hold points need an agreed release process. Define notice, attendance, waivers, retests, report review and shipment approval befo...
Read the guide
20 Oct 2026
Substation Transformer Bushing CTs: Ratio, Burden and Terminal Scope
Substation transformer bushing CT requirements should identify each location, core and duty. Connect ratio and burden evidence to the secondary-terminal hand...
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19 Oct 2026
Motorized DETC or OLTC? Transformer Tap-Changer Scope
Motorized DETC and OLTC describe different tap-changing duties. Separate the changer, motor drive and controls, then use a scope matrix to confirm interfaces...
Read the guide
19 Oct 2026
Removable Transformer Radiators: Interface and Supply Scope
Removable transformer radiator procurement needs a controlled drawing and clear acceptance record. Review mechanical fit, cooling-design responsibility, liqu...
Read the guide
19 Oct 2026
Pad-Mounted Transformer Loop Feed: Three-Phase Switching Scope
Pad-mounted transformer loop feed does not define the complete switching package. For a three-phase unit, compare one-line drawings, switch functions, rating...
Read the guide
18 Oct 2026
Substation Transformer Conservator and Breather: Supply Scope
Substation transformer conservator and breather scope requires more than a component list. Confirm the preservation arrangement, oil-expansion basis, air sep...
Read the guide
18 Oct 2026
Mineral-Oil Substation Transformer DGA: Agree the Baseline
Mineral-oil substation transformer DGA needs an agreed baseline. Define sample stages, methods, reference records and technical review responsibilities befor...
Read the guideCompare quotations
Put the proposals
on the same basis.
A lower price is only comparable when the proposed equipment and supply scope match. Record differences and resolve them before ordering.
Equipment
Compare capacity, voltages, phase, frequency, impedance, cooling and installation requirements against the same specification.
Documents and testing
Identify the proposed model, drawings, required test reports and any mandatory approvals. Check what is included and excluded.
Commercial scope
Compare quantity, delivery term and named place, packaging, transport, lead time, payment and warranty in writing.
Project documents
The right document. For the right model.
Tell us which documents your project needs. Availability and applicable scope are confirmed for the proposed model and configuration.
Outline and connection drawings
State the installation, cable-entry and clearance requirements you need to check.
Request for your projectTest and approval documents
Name the required tests, standard or approval, and the model or configuration concerned.
Request for your projectRequest documents for your proposed configuration
Include the model or product type, capacity, voltages, frequency and destination. Ask for the report number, date and test scope so you can check that the documents match the proposed configuration. An individual report does not establish certification for every model or destination.
When reviewing a document, match the legal entity, model, rating, applicable scope and issue date to your proposed equipment.
Read the certificate-scope guideOpen the document centreYour project / next step
Good decisions start with clear requirements.
Send the details you have. We can start the conversation while the remaining requirements are being confirmed.
Discuss your project